Unmasking Hidden Epitopes Using the Pressure Cooker

INTRODUCTION

Several methods have been developed to “retrieve” antigens that have been masked by fixation. The principle behind the pressure cooker method described here is to use extended periods of heat to break some of the subcellular structures that block antibody access. This approach is appropriate for handling specimens on glass slides. The major advantages of the pressure cooker method are the ability to handle a large number of slides simultaneously, the convenience of using metal racks, and the avoidance of any hot spots that are found in the microwave. Be aware that any of the antigen retrieval methods should be avoided wherever possible, because they may introduce artifactual false-positive staining. Methods for antigen retrieval are specific for each antibody/antigen combination. No attempts to establish quantitative data following these methods should be considered.